CVE-2026-16723 Remote Code Execution in fastjson 1.2.68–1.2.83
Remote attackers can execute arbitrary code via deserialization in fastjson under default settings, requiring immediate library upgrades.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-16723?
CVE-2026-16723 is a critical unsafe deserialization vulnerability in Alibaba Fastjson, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83. This vulnerability is exploitable under fastjson's stock default configuration — no AutoType enablement required, no classpath gadget required.
Which versions are affected by CVE-2026-16723?
2 open source packages ship an affected version, including com.alibaba:fastjson.
| Package | Affected | Fixed in |
|---|---|---|
com.alibaba:fastjson Maven | From 1.2.68 to 1.2.83 | None |
com.alibaba:fastjson Maven | From 1.2.68 to 1.2.83 | None |
How do I fix CVE-2026-16723?
No fix has been published for CVE-2026-16723 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-16723 being exploited?
There is no known exploitation of CVE-2026-16723 in the wild and no public exploit code.
Public exploit code: 14 proofs of concept on GitHub.
Sources
Also known as GHSA-crf3-v9rr-v7hj.